It is likely that any perceived improvement is due to expectation bias, while any perceived degradation is due to overheating components with the soldering iron.

I don't think I overheated other components. There was at least 5mm from other miniature components and I used the iron head for maximum 2 seconds so I don't think the heat would have reached the smallest miniature caps .

The most difficult was the output non polar caps those 8 being surrounded with smaller miniature caps and components . Until now all 8 outputs work great having connected 4 amps .